


Black Knight the Babysitter

by orphan_account



Category: Fire Emblem Heroes
Genre: Background Arden/Shigure btw, Either way Legion and Black Knight/Zelgius have an interesting dynamic, It’s interesting to me, It’s the Tempest Trial Reward Black Knight, Legion’s an orphan taught to kill in order to survive and please the head of his orphanage, M/M, Not the Zelgius you summon from the Gasha, They’re both killers who live to please someone they see above them, When you strip away the circumstances, Zelgius is an abused orohan who strives to outdo his teacher but murders anyone for his master, but chapter two is straight porn sorry not sorry, oh btw the first chapter is fluff and learning, so comparing Legion’s childish behaviors compared to how mature Zelgius makes himself, sorry for the confusion but the Zelgius in reference here is the TT reward one
Language: English
Status: Completed
Published: 2018-03-08
Updated: 2018-04-12
Packaged: 2019-03-28 04:50:35
Rating: Mature
Warnings: Graphic Depictions Of Violence
Chapters: 2
Words: 4,820
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/13896642
Author URL: https://archiveofourown.org/users/orphan_account/pseuds/orphan_account
Summary: In which the Black Knight finds someone who is oddly accepting of him, and Legion finds a friend, because the Summoner asked the Black Knight to watch over Legion.Zelgius hates to admit that they are very alike, but Legion is all too happy that someone understands.





	1. You’re Just Like Me

**Summary for the Chapter:**

> Legion asks some questions, and answers some of the Black Knight’s own. They end up more familiar than expected.

The Black Knight was accustom to difficult tasks, but this is probably his most perplexing one yet. The Summoner (honestly, if it hadn’t been some contract bound garbage, the Black Knight would have left by now for his homeland to finish his mission) had politely requested that he watch after a member of his squad for a few hours, just to keep him out of trouble. The branded is well aware of his comrades - there was another knight who was powerful, but slow, named Arden, a mysterious boy with a powerful song named Shigure, and a man whose description is more in line with “Wild Animal” than anything else: Legion. Legion was a wild card, because he was impulsive, rash, and took caution as ignorable recommendation more than anything else. He was violent, but aware of his choices - Legion chose to destroy just as much as he chooses to keep his comrades alive. He was like a giant child, temper flaring when things didn’t go his way, raging through property damage to express frustration, but able to be pacified by simple things.

The Black Knight was in charge of Legion for a few hours, as Arden and Shigure had better things to do than keep this man child from causing a mess.

The branded was well aware of Legion, of course - they have fought together and the bloody wake of bodies that Legion leaves behind reminds him of a dog that had been digging holes to find a bone - Legion gored people like he was searching for something in their corpses. A more philosophical man would perhaps make some kind of observation on how this is reflective of Legion's past, or how it represents some part of his tragic back story, but the Black Knight didn't care too much to try and figure that out. As long as the enemy dies and the battles are won, the branded knight assumes both of them are completely fine with simply fighting side by side. He doesn't know much about the masked maniac otherwise - rumor has it that Legion is an orphan, but that's not for the Black Knight to know. Not unless Legion decides to share it with him, anyway. Perhaps he can sympathize with a lack of good parental guidance, considering his own past, but that's not for him to decide either - he's not even sure that Legion is an orphan.

Which leads to now, where the Black Knight is standing off to the side of the training grounds, watching with an unblinking stare as Legion rips apart... himself. The odd ability of Legion's cloning was interesting to watch in action, as one clearly out does the other, the one in full offense leaves blow after blow, leaving the weaker clone with heavier and heavier damage until...

There’s a roar from the Legion that hasn’t let up its attacks as it effectively slices the clone in half, blood spattering the dirt as the weaker falls to the ground. The Black Knight’s stare is unwavering as he watches the winning Legion look over the split corpse, then hustle over to the top half. The winner lifts the mask up off the head, then begins vigorously slamming the blunt end of his ax into the dead clone’s face, over and over, the sound of cracking bone and sloshing brain drowing out the birds singing near by. After a moment, Legion’s finished with the destruction of the other’s face, pulling the clone’s mask off, standing up, and punting the top half of the body out of the training grounds barriers and into an unused, dug out pit that just serves as a trash bin for unrepairable weapons and the occasional corpse. Legion does the same with the lower half, favoring to kick the legs across the dirt like a child rather than pick them up and dump them properly.

The Black Knight doesn’t say anything, but Legion tilts his head as he looks over the armor clad general.

“Thats how we trains! We fights overselveses until ones of us dies. Then practiceses over!” The masked man declares, while Zelgius simply raises a brow under his helmet. Interesting. Panting like a ragged dog, Legion strides over with some kind of pride, then gets... uncomfortably close, eyes attempting to lock with the Black Knight’s eyes. It doesn’t work, but Zelgius does find himself shoving Legion away, either.

“We tolds of youses. Youses the Blacks Knight, Uwehehe!” The laugh throws Zelgius off for a moment, but not as much as the statement of who he is. Shouldn’t Legion be aware of who he is now? Before he can open his mouth to protest, Legion has more perplexing things to say.

“Youses and Legion are the same. Yes yes yes! We ares alike.”

The Black Knight is frowning, not that Legion could tell.

“I highly doubt that. What makes you similar to me?”  
“Legion also hases bad families. We don’ts know ours parents, but Legion knows hows to fight. We follows our motherses, but alls we know is fighting.”

When put like that, perhaps, he can see the similarities. Bad family life, outcasted, a one trick pony who only knows how to fight, and loyally follows the orders of one person... simplified, yes, but accurate. Legion seems proud of this, almost beaming, but Zelgius decides to avoid talking about the past for now.

“Come, head inside. You need to wash up.”

Legion didn’t agree to this, hand clutching the ax as if the berserker was to attack, but instead just nods solemnly and returns inside at the side of the knight, who leads him to the wash room. Not that the Black Knight cared enough about Legion to keep him clean, but he might as well save the servant types the trouble of cleaning later. Not that he’s being nice to anyone, or anything.

Perhaps he needs less time around Legion, if that’s how his thought process is going.

The masked man is tasked with cleaning his blade, as well as washing blood off his mask and forwarms. Zelgius doesn’t say much in regards to the other, just making sure nothing gets destroyed in the process. Legion, however, was having none of that today.

“Black Knights, wheres do youses come froms?”   
“... I am from Daein.”  
“What’s it likeses?”

There’s a pause before the Black Knight speaks again, favoring to watch as Legion cleans and sharpens his ax.

“As it seems to be with everyone here, at war. Violent.” That’s more or less a general overview, but the Black Knight would rather not have gotten into the massive pain that is his country and his wars. Legion just gives him a look, then returns to grinding his ax against the whetstone.

“Your ax seems rather oddly crafted, Legion. What is the reason for that?”  
“Legion mades it ourselves!”  
“You made the ax yourself?”  
“Yes yes yes! Made it whens we weres small.”

A child making an ax to defend himself. The Black Knight shakes his head at the thought.

“Whys the Black Knights here and nots in Daein?”  
“Because I was summoned here, just like you. Bound to fight for another that isn’t my master.”  
“Hm, Legion wasn’ts summoned. We fight and fight until we losts, then summoners recruiteds us!”  
“I suppose our manners of being summoned are both unorthadox compared to most.”  
“We are the sames.”

That again. The Black Knight sighs, but doesn’t let himself get annoyed.

“Without context, we are similar to a degree.”  
“Legion is okays with that!”

After that, there’s only the noise of an ax being sharpened and nothing else, until the berserker is pleased with the blade’s repair. Satisfied with the result, Legion yawns, standing up with his ax in hand. The Black Knight nods, and Legion’s tailing after the branded knight as he heads for the library.

——

It’s about an hour before the summoner returns, surprised to find Legion lazily flopped on the Black Knight’s lap, the berserker snoring peacefully as Zelgius finds him invested in a novelization of the history of Marth’s time, a hand rested on Legion’s head.

The summoner smiles before disappearing from the door frame, noting that the bonding exercise worked.


	2. And Then They Boned

**Summary for the Chapter:**

> My hand slipped I swear.

After that time in the library, Legion decided the Black Knight was his new favorite person. Just because Legion decided he liked Zelgius doesn’t exactly mean Zelgius warmed up to the masked man - but, despite how he shouldn’t be getting close, it’s difficult to keep your composure when the man who can duplicate himself is clearly interested in you. Legion was physical with his affection and his clones were just as bad as Legion himself, so much so that it took the Black Knight more time than he’d like to admit learning which Legion was the main one. There was a moment of frisky, playful banter in a hallway that led to that mask tilting up and the helmet pushed away, and...

If only they could have remained in private, then maybe that mask would have slipped off along with some other things. However, someone had alerted their presence with noise, and both of them scrambled to adjust dishelved appearances for the sake of ‘nothing happened here’. This was starting to get more common, hard pressed kisses from barely moved head coverings in places a bit too communal to be comfortable, but with no one around, it was enough to risk getting lost in. Sometimes, the Black Knight found himself pinned to the wall, hands uselessly clawing at Legion’s clothed back - but other times, Zelgius had enough, and practically dragged the other into empty halls, just to leave Legion whining. Never any further than sloppy make outs that only serve to tease, but never give release.

It was getting harder to ignore Legion, however, and Zelgius knew he didn’t deserve such things. At first, it disgusted him how his imagination wanted to continue those romps, watch every little twitch and hear every under the breath swear. Watch Legion shudder with loud cries when he cums, leave marks upon marks for the Black Knight to solidify that the woman who trained Legion into the monster he is no longer had control of him. There’s hypocrisy there, since Zelgius is aware of his loyalities, but in Askr... perhaps, he can loose the reigns of one master in favor of letting his masked maniac claim him - and that line of thought was even more disturbing than the idea of how possessive the knight sounded. The Black Knight knows full well the moment that his master is called to this realm that whatever he and Legion have is extinguished, no matter the desires otherwise. He knows better, so much better, because even without his master, Zelgius is fully aware what will become of him should anything get in the way of their fragile, but blossoming relationship.

Happiness and love were not for him, nor was someone who understood what it was like to hate your birth family, never to truly take your spot and when it comes, it’s too late and you’re already a monster. In contrast to the day time, however, Legion would invade his room after the sun had set and everyone had gone to bed, leaving the pair in the dark, and they’d simply sit next to each other. At first, it was in full outfits, but time wore on and soon Zelgius, without his armor, brand open to the world, and Legion, mask off, a face never seen one ray of light away from being exposed, sat in peaceful silence.

In the darkness, it was comfortable - their insecurities were open, but neither of them made any moves. Just pleasant silence and quiet bonding, comfortable enough with the other to lay the secrets bare, but never probing, leaving it without any questions. It became a nightly thing, until Legion whispered a story of his orphanage to break the silence one night, and Zelgius replied with a story of his own, quietly regaling more personal information in the darkness. At some point, they started sitting closer, then hand in hand, waiting out nightmares and insomnia during the young hours of the night. This quiet, calm during the nights made the occasional make out mean more, feel more, and Zelgius didn’t want to admit he loved it. In the day, they were back to normal - Legion’s endless murder spree along with the Black Knight’s deadly swordsmanship, “begrudgingly” getting along while Arden still tried to get around the fact Shigure was his sweetheart and had permission to call him as such.

It had been a massacre of the Emblian troops as the Black Knight and Legion stormed the front lines, leaving even Surtr surprised at the dent in the forces the two of them had made. Legion attempted to square up against the king of flame, only to be horribly disappointed at the lack of damage he could do thanks to the ward - not that the masked man could do anymore, since the Black Knight had snagged Legion by the collar, dragging him away in order to wedge his defenses between them. It was enough to deflect the foe’s attacks, but Zelgius didn’t go unharmed from it.

Neither spoke a word of what occured on the battlefield that day, favoring to ignore each other completely to avoid the subject. It wasn’t until that night, when everyone had fallen asleep, that the Black Knight broke their silence and snuck into the other’s room, only to surprise Legiom, who had fully expected to be unwelcomed. The Black Knight locks the door behind him before rushing over, hands clamped onto the masked man’s shoulders.

“Legion, what the hell was that?”  
“We coulds have takenses him...”  
“Not the point. You would have been slaughtered, Legion. I don’t care if that infernal device keeps us contract bound and unkillable, I’m not letting you suffer that kind of pain from a reckless mistake.”

There was a small bit of silence, and the Black Knight laments the fact his tone makes him sound like a worried parent. He’s not Legion’s family, nor does Zelgius feel he deserves to be, but the stern worry was prevelent in his voice and his actions - hell, he still has Legion pinned, eyes glaring out from his helmet. The masked maniac’s confused, clearly, gears in that warped head spinning fast. It didn’t make sense. Why would anyone care about Legion’s well being? From the stories that they shared, the orphan’s caretaker raised him into a murdering monster - neglect and abuse is what made Legion into what he is. What gives Zelgius the right to act so protective of and nice to the masked maniac, when he can’t even understand why anyone would want to be like this towards him?

“Why?”

The question leaves the branded knight a bit surprised, but the hurt confusion in Legion’s eyes is painfully obvious. The Black Knight makes a heavy sigh, letting an armored hand trace a finger down the side of the other’s mask. Why would Zelgius care about Legion? Why was he worried? The answer was simple enough, but the reluctance to leap to that conclusion, fear of this simple thing being ripped away at a moment’s notice... Perhaps the Black Knight ought to know better than letting himself worry - after this, they wouldn’t ever meet again - but he remains there, frustated, wondering if it’s easier to let this go and forget about it. No, that has to be thrown out - so what if a time comes where this kind of affair is impossible? If anything, when it’s time for them to return to their proper times, Legion will at least know what it’s like for someone to care.

“Because I wish be your shield. You can’t expect for me to not find our time together for naught - our bond is stronger than steel, and you know that as well as I do.”

The masked berserker goes quiet for a moment, staring hard at the Black Knight with an undetermined expression. Careful hands reach up, pushing the mask out away from his mouth, revealing the chapped lips and mild scarring, breath heavy. In turn, the Black Knight mirrors the gesture, pulling his helmet off, but not stopping at the typical area - it’s all the way off, navy hair a bit frazzled from being under the helmet, but dark eyes now apparent all the same. The helmet’s practically tossed aside, but it lands in a pile of unwashed clothes that Legion had yet to clean up. A brief pause, and it’s just like before, lips meet and Legion whines when he’s met with a sudden harshness, feeling a hand in his hair and another on his hip, a knee attempting to slip between the masked man’s legs.

By now, both of them have this part down.

The berserker’s hands attempt to find their way around - a few awkward pats, but one’s settled into Zelgius’s hair and the other’s trailing fo his hip, while the branded simply bit at the other’s lip, earning some kind of pent up, deep noise that seemed to have been stuck from before. Typically, Legion’s more of a fighter during these romps, but it seems something has gotten him to lighten up and stick to what the other could only refer to as submissive behavior, running his tongue over the teeth currently biting him. Zelgius takes advantage of this, pressing a bit deeper, gently raising his knee a little more to jostle the other into another moan. Legion’s a bit helpless, and it’s enough the Black Knight decides that perhaps the other hasn’t gotten past this part. Not that he can say the same.

A small miscalculation results in teeth clicking against each other, the sensation weird enough for both parties to pause for a brief moment. Zelgius blinks once, getting a face full of panting Legion, who actually seems to be keeping up with brushing his teeth like was requested after the first few times they took to making out in the halls. Part of this pleased the knight, somehow, like his worry and care for the other mattered. After the brief hesitation, Zelgius attempts to pull Legion from his distracted thoughts with a kiss, then another, and a third, getting longer and more drawn out until he gets a response back. That dominate streak that the masked man was hiding shows itself all of a sudden, with a rush of energy that almost takes Zelgius off guard, resulting in more playful kisses that start trailing downwards, to what’s exposed of the other’s neck. The masked man makes a disappointed growl, playfully knocking on Zelgius’s armor with a knuckle as they share a brief kiss. 

“Fine. Hold a moment.” The Black Knight huffs, breaking away for just a moment to fiddle with the latches and armor, shimmying out of the armor that makes his namesake. Legion seems enjoy watching his partner strip, then to take the hint and stripping off his own clothes. It’s silent as the things in the way get pulled off and set aside, only sparing glances to see how the other looked. Legion finds himself pushing his mask down to stare, so pleased at what he’s gotten, only to catch Zelgius examining him back.

Both of them are littered with scars, but that’s a none issue.

Before long, they’re back on each other - Legion makes the first move, grasping Zelgius by the shoulders and moving his mask away, rekindling the previous flames from earlier. He’s rewarded with a gasp, and his newest affection resting hands on Legion’s waist. This was a temporary bliss, but it was nice to indulge. The poor wall that Zelgius had been shoved against now serves as their base, allowing the black knight something to lean against as now bare hands grab at Legion, one trying to steady his back while the other grabs for his ass, pleasantly surprised that there is something to grab. For some reason, Zelgius never expected Legion to have a plush butt, since his berserker outfit always made it seem flat.

Legion whines, still trying to keep his control, and goes for the weak spot. Their romps have taught him the Black Knight’s neck is excessively sensitive, and that he’s no stranger to pain - thus prompting Legion to pull out the fact he knows Zelgius loves being bitten. The masked man pulls away from the kiss, then quicky shoves his face in the crook of the other’s neck, biting down hard. The noise that leaves the Black Knight is somewhere between a squeal, a moan and a breath gasp, but it is not a noise he is proud of. Legion just smiles against the skin, apologetically lapping at the mark he just made (and secretly proud of the fact he may or may not have drawn blood). In retaliation, Zelgius squeezes the other’s ass again, only to then force Legion’s hips closer, the action rendering half hard cocks to rub against each other and stop the masked man in his tracks. The Black Knight takes advantage of this, digging his teeth into the skin between Legion’s neck and shoulder. That generates a whimpering from the masked man, and the Branded is rewarded with the hand in his hair pushing him closer. If nothing, the masked man has wonderful collar bones, which Zelgius is going to bite on the whole time. That was certain. 

“Bedses.” Legionmumbles, breath heavy as his hands move from their spot, attempting to keep his legs steady as Zelgius keeps leaving dark, heavy bruises down Legion’s neck and on his shoulders. It takes a beat for the general to realize what his dearest said, prompting him rest his arms under that suprisingly nice ass and carry Legion back to the bed. The masked man yelps at being picked up, whimpering the whole time from a mix of being carried and the lovely attention Zelgius is paying him. There’s a bit more shuffling, since Zelgius breaks away to get the oil he keeps in his armor (for reasons other than sex, obviously) to make things easier. The mask is still slipping off, having being jostled a bit from the earlier necking, revealing more disgusting scarring over Legion’s face. Nicks, cuts and partial burn marks hide on the flesh under the mask, and the Black knight isn’t suee how he feelt about it yet. The maniac must not have noticed yet, because he’s still panting and hard, facing where he thinks Zelgius is. So cute, how eager Legion is, and it almost makes the Black Knight feel bad for this lost of possible innocence. Almost. Legion’s a consenting adult, he reasons, if he doesn’t like something he’ll say no. However, just to be sure... As the general prepares his fingers, he leans down to Legion’s ear, whispering.

“Tell me if I need to stop. I don’t want to hurt you.” He mutters, kissing the side of the other’s head, waiting for some kind of approval. There’s a beat of silence, and Legion nods, rapidly, only to then roll his hips up into Zelgius’s as a plea. The Black Knight seems fine with that much, and presses his first lubricated finger into the other’s ass. That gets a favorable response, mostly in the form of a paritally suprised gasp and his cock twitching, making Zelgius smile a bit. How cute. He pauses, just to make sure the masked man is okay, then begins to rub the walls constricting his finger. This is making Legion squirm and groan, which then causes Zelgius to go back into reassurance, gently helping accommodate that new feeling.

“Easy, Legion, you need to relax.” Zelgius reassures, voice quiet as his free hand rubs the other’s head, gentle kisses being placed over previous bites. They get a bit sloppy, and Zelgius decides to move a bit faster, now that Legion’s stopped fidgeting so much. He debates adding a second digit, briefly, until he starts getting whining because he stopped moving. The Black Knight devides he’s ready, careful to reassure the other as they go. For all he knows, Legion’s a virgin - or... No, now is not the time. “Relax, it’ll hurt more if you’re tense.”

Legion takes the second finger well enough, and Zelgius takes it as time to actually move this along. He starts to scissor right away, dragging his fingers down, almost fully out, only to shove them back in and keep going. The masked man’s still fidgetting, but the quiet, wonderful noises leaving him are more than perfect. As a reward for taking it so well, Zelgius kisses him, hard, then takes a moment to adjust positions. The assassin groans into the kiss, hands that previous grabbed the sheets now carding in the Black Knight’s hair, neither really paying attention to the way Legion’s cock dribbles precome against his well earned muscles. Perhaps, some other time, Zelgius needs to pay well deserved attention to those, but now was not the time. Not yet. They’ll focus on being kinky later.

The scissoring comes to a stop once Zelgius has to pause to grab the lubricant again, carefully splashing more onto his fingers. The Black Knight was fine with ignoring his own needs, since Legion looks far too adorable like this, panting and begging as he grinds against the fingers in him, and that mental image might be used when he’s truly alone, but right now was to focus on the other. The masked man fusses again, only to make an unexpectedly loud groan at a new finger being added. Legion’s not one for begging, but even with that third finger, he wants more. “Morses, morses, morses, please! W-we wants moreses!”

The Black Knight won’t say no to that. A few more strokes with the third finger earn more flustered begging, only to be met with a whine and a growl at it being removed. “Patience, Legion.”

Satisfied at the amount of lubricant used (which, is probably more than he needs, but Legion’s still not used to it), the Black Knight takes a moment to adjust, then pressea the tip of his (heavily oiled) cock into Legion’s ass. This is met with groaning and a bit of wincing, but there’s no request to stop. The masked man attempts to press forwards, take more than Zelgius gave him, but the Black Knight stops that right away with a hand on Legion’s chest, squeezing one of his pecs - which stops the other long enough to make the slide in less painful. It’s a stretch, at least, making Zelgius fear he didn’t prepare Legion enough, but if anything it seemed the other loved the feeling. They’re both still, for a moment, making sure the masked man’s ass can take it, and Zlegius gives a sharp, hard thrust.

If he could see it, Zelgius would know that alone causes Legion to roll his eyes back, his tongue sticking out of his mouth as the Black Knight continued to slowly start fucking him. The masked man’s cock twitches, slightly bouncing from each thrust, completely neglected by accident. He’ll have to admend that, but the bed loaned to Legion by the Askr army is taking the abuse from this quite well, despite slamming against the wall. The neighbors won’t be happy, between Legion’s cries and the bed, but that’s for not now. The hand he had used to finger Legion initally now wrapped around the neglected cock, giving it a few strokes before a throaty, jagged moan erupts from Legion, who has practically had the mask fucked off him. It’s crooked, almost completely off his head, but Legion’s so wrapped up in pleasure he doesn’t notice. In fact, he’s still begging for Zelgius to keep going, which the Black Knight obliges to, despite getting cum all over his stomach and chest. Seems someone hasn’t gotten off in a while.

The masked man goes limp for a moment, his cock softening but the walls of his asshole clenched around Zelgius, who decides he’ll just finish himself off later and attempts to pull out. This removal attempted is met with Legion hooking his legs around Zelgius, voiceless, and shaking his head. Understanding, the Black Knight takes his time to finish, being less noisey than Legion and only gasping when he cums, mentally feeling bad for doing so. Legion sighs, content, still not aware of his askew mask, and lets the Black Knight go, trying to stay awake. Feeling the need to be the responsible one, Zelgius attempts to leave the bed, but is stopped by his dearest. Zelgius just reaches up and adjusts the other’s mask, which earns him an appreciative hum. Alright, guess not.

Though, that’s probably the best sex he’s had in years, even if it didn’t seem so later, when he and Legion have this affair down to a science. The Black Knight sighs, softly, letting Legion cling to him, and pets his hair.

Explaining tomorrow will be hell.


End file.
